Propeller



I April 7, 1931. K. F. 'rARz PROPELLER Filed April 14, 1930 3 Sheets-Sheet 1 K451 EJ774192 WITNESS: 96a

K. F. STARZ PROPELLER April 7, 1931.

- Filed April 14, 1930 5 Sheets-Sheet 2 'ATTonNlY Aprll 7, 1931. K. F. STARZ 1,300,112

I PROPELLER Filed April 14, 1930 3 Sheets-Sheet 3 ffAkL 5 77m:

. I mvem on M 486: 0424. o r I wrrflsss: M A'r-rcmusv Patented Apr. 7, 1931 UNITED STATES PATENT OFFICE Application filed April 14, 1930. SerialNo. 444,307.

This invention relates to improvements in propellers, the general" object of the invention being to provide means whereby the pitch of the blades of the propeller canbe 5 varied from the cockpit of a craft so as to regulate the speed of the craft through the set of the blades, which will permit the craft to E operated with the minimum" amount of This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawings and 15 specifically pointed out in the appended claims.

In describing the invention in detail, reference will be had to the accompanying drawings wherein like characters denote like 2 or corresponding parts throughout the several views, and in which T Figure 1 is an end view showing the central part of a propeller constructed in accord ance with this invention.

Figure 2 is a section on line 2-2 of Figure 1.

Figure 3 is a section on line 3-3 of Figure 2. I

Figure 4 is a section on line 44 of Figure 1, showing the parts set with the blades in a neutral position.

Figure 5 is a section on line 5-5 of Figure 1, with the parts in the same position they occupy in Figure 4. a

Figure 6 is a view similar to Figure 4 and Figure 7 is a view similar to Figure 5, but

showing the parts in different positions.

Figure 8 is a view similar to Figure 4 and Figure 9 is a view similar to Figure 5, but showing the parts in other positions.

In these drawin s, the numeral 1 indicates the pro eller she and 2 indicates a hub mounte on the shaft and formed with a sleeve 3 which extends over a part of the tapered, as shown.

, The hub is formed with a number of hollow spokes 4 over which the stems 5 of the blades fit, so that the stems are rotatably arranged "60 on the hub. A flange 6 is rotatably arranged shaft, the hub and sleeve and the shaft being on each end of the hub, each flange being formedwith the extensions '7 which have holes 8 adjacent their ends for receiving the trunnions 9 on a collar 10 formed on each stem 5. Each stem 5 is clamped to a spoke by a split collar 11, the bent ends of which are connected together by a bolt 12. Thus each stem is firmly connected to a spoke and the two trunnions of each stem enter the holes 8 of a pair of extensions 7 of the flanges 6. A number of levers 12 is pivoted to the hub adjacent their outer ends, as shown at 13, each lever being arranged between a pair of the spokes and each lever passes through an openin 14 formed in each flange 6. The inner en s of these levers carry the rolls 15 which engage the cam grooves 16 in a collar 17 mounted on the sleeve 3 and having a groove 18 therein for receiving a shifting fork (not shown), this fork being connected to a lever or the like in the cockpit. Thus it will be seen that by shifting the collar 17, the cam grooves 16 will, through the rollers 15, shift the levers 12, and as these levers pass through holes in the flanges 6, this shifting movement of the levers will move one flange in one direction and the other in the opposite direction so that the blades will be partly rotated and thus their pitch will be changed.

Fi res 4 and 5 show the parts in a central position, Figures 6 and 7 show the parts shifted in one direction beyond a central position and Figures 8 and 9 show the parts shifted in an opposite direction beyond a central position.

Thus I have provided simple means for adjusting the pitch of the ropeller blades so that the speed ofthe cra can be controlled by regulating the pitch, and thiswill permit the craft to be driven with the minimum amount of fuel as the internal combustion engine can operate at its most economical rate of speed at all times through a constant load, low pitch at take-off and high pitch in flight.

It is thought from the foregoing description 95 that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combination and arrangement of the several parts, 190

provided that such changes fall within the scope of the appended claims. What I claim is 1. A propeller comprlsinga shaft, a hub on the shaft, a pair of flanges rotatably arranged on the hub, propeller blades having their stems arranged between the flanges with their ends rotatably arranged on the hub, trunnions on the stems and the flanges having openings therein receiving the trunnions and means for moving the flanges in opposite directions to partly rotate the stems to change the pitch of the blades.

2. A propeller comprising a shaft, a hub on the shaft, a pair of flanges rotatably :arranged on the hub, propeller blades having their stems arranged between the flanges with their ends rotatably arranged on the hub, trunnions on the stems and the flanges having openings therein receiving the trunnions, means for moving the flanges in opposite directions to partly rotate the stems to change the pitch of the blades, such means compris-- ing a collar slidably arranged on a part of the hub and having cam grooves therein, levers pivoted to the hub and passing through openings in the flanges and rollers on the levers engaging the cam grooves. x

In testimony whereof I aflix my signature.

' KARL F. STARZ. 

